Non-Invasive Cardiac Testing

Question 1

Threshold for “angiographically insignificant” coronary obstruction.

Answer 1

<70% stenosis.

Question 2

Angiographically significant (>70% stenosis) three-vessel disease may produce false-negative vasodilator stress test due to ___.

Answer 2

Balanced ischemia.

Question 3

Exercise (treadmill) stress test modalities:

Answer 3

1. EKG.
2. TTE.
3. SPECT.

Question 4

Duke treadmill score components:

Answer 4

Exercise time - (5 x maximum ST-segment deviation in mm) - (4 x exercise angina [0 = none, 1 = non-limiting, 2 = exercise limiting]).

Question 5

Duke treadmill score interpretation:

Answer 5

Low-risk: +5 or greater
Moderate-risk: -10 to +4
High-risk: -11 or less

Question 6

Pharmacologic stress test modalities:

Answer 6

1. TTE.
2. SPECT.
3. PET.
4. MRI.

Question 7

Agents used in pharmacologic stress testing:

Answer 7

1. Adenosine/regadenoson.

2. Dobutamine.

Question 8

Relative contraindications to adenosine/regadenoson stress testing:

Answer 8

1. Bronchospasm.
2. High-grade AVB.
3. SSS.
4. Bradycardia.
5. Severe AS.
6. Seizure disorder (reversal agent for Regadenoson (aminophylline) has risk of seizure).

Question 9

Mechanism of adenosine/regadenoson:

Answer 9

Promotes vasodilation via cAMP, leading to coronary steal. Stenosed coronary arteries are unable to dilate in response to adenosine.

Question 10

Mechanism of dobutamine:

Answer 10

Increased cardiac workload via positive chronotropy/inotropy. (Beta-1 agonism).

Question 11

Relative contraindications to dobutamine stress testing:

Answer 11

1. MI in the past 48 hours.
2. History of malignant arrhythmia.
3. Severe AS.
4. HOCM.
5. Severe HTN.
6. Severe PAH.

Question 12

HR and RR requirements for cardiac CTA:

Answer 12

1. HR 60-70 (make require BB).

2. 5+ second breath hold.

Question 13

Utility of cardiac CTA in asymptomatic, low risk, and moderate risk patients:

Answer 13

1. Cardiac CTA is not indicated in asymptomatic patients.
2. Cardiac CTA has a high NPV (>99%) in low-risk patients.
3. Cardiac CTA is reasonable for risk-stratification in moderate-risk patients.

Question 14

Coronary MRI is preferred over cardiac CTA in:

Answer 14

1. Post-CABG vessel imaging.

2. Evaluation of suspected/known congenital or acquired coronary anomalies.

Question 15

Viability testing modalities:

Answer 15

1. SPECT.
2. PET.
3. TTE.
4. MRI.

Question 16

Viability testing indication:

Answer 16

To determine the viability of ischemic myocardial tissue.